Burton: Online Algorithm (partial)
NextAction(initial state ???target state ?, compiled system Sí)
Select unachieved goal: Find unachieved goal assignment with the lowest topological number. Otherwise, return Success.
Select next transition: Let ty be the transition graph in S for goal variable y. Nondeterministically select a path p along transitions in ty from ei to ef. Let SC and CC be the state and control conditions of the first transition along p.
Enable transition: Control = NextAction(?,SC,Sí). If Control = Success then state conditions SC are already satisfied, return CC to effect transition. If Failure return it. Otherwise Control contains control assignments to progress on SC. Return Control.